What does omnis mean?

Answer 1

Omnis is the nominative and genitive form of the Latin adjective omnis, omne, meaning "every" in its singular form and "all" in its plural form. The masculine and feminine forms of the word decline identically, but the declensions change in its plural M/F form and in the neuter forms. A good paradigm of the word is available here:

Like nouns, adjectives in Latin have gender, but some adjectives declines identically in their Masculine and Feminine forms.

Answer 2

Answer

A combining form denoting all, every, everywhere; as in omnipotent, all-powerful; omnipresent.